Field of the Invention
The present invention relates generally, to the field of physical/chemical reaction engineering equipment and relates more specifically to an industrial microwave ultrasonic reactor.
Related Art
Microwave is a type of electromagnetic wave having a wavelength in the range of those of infrared ray and ultrasonic wave, and has a wavelength in the range of 1 m to 1 mm and a frequency being 300 MHz to 300 KMHz. Microwave heating is to induce molecular polarization and dipole rotation by means of interaction between microwave and molecules, so as to cause rapid movement of molecules. Therefore, microwave heating has strong penetration effect and can reach the internal of materials, so that the temperature inside the materials is rapidly increased, and ingredients are freely released, thereby achieving the purpose of removing or extracting the ingredients, and meanwhile, the reaction rate is significantly increased, and the chemical reaction activation energy is reduced. When microwave meets different media during transmission, due to different main properties of the media such as the dielectric constant, the dielectric loss factor, the specific heat, the shape, and the moisture content, the reflection, absorption, or penetration effect is generated; therefore, the absorbed electric field energy is different, and selective heating may be performed. An aqueous material is generally an absorbent medium, and can be heated by microwave.
Ultrasonic wave is a type of mechanical wave having a vibration frequency greater than 20 KHz, utilizes mechanical effects to improve the dispersibility, and can allow heterogeneous reactions to be carried out smoothly. Propagation of ultrasonic wave needs an energy carrier, that is, a medium, and during transmission, an alternating cycle of positive and negative pressure exists. In the positive phase, the medium molecules are squeezed to increase the original density of the medium, and in the negative phase, the medium molecules are few and scattered, the density of the discrete medium is decreased, and acoustic cavitation occurs between the solvent and the sample, resulting in formation, growth, blasting and compression of bubbles in the solution, so that the solid sample is dispersed, the contact area between the sample and solvent is increased, and the mass transfer rate of the object from the solid phase into the liquid phase is improved. Secondary effects of ultrasound such as mechanical shocking, emulsification, diffusion, and crushing all are beneficial to all-round full mixing of the reactants, so that a stirring effect more effective than that of common unidirectional stirring is achieved.
Reactors using microwave and ultrasound in coordination for impurity removal, purification, catalyzing reactions, and strengthening chemical reactions are widely used in the technical field of chemical engineering, for example, Chinese Utility Model Patent No. 200920282481.4: Multi-functional Ultrasonic Microwave Chemical Reactor; US Patent No. US2009/0178914A; Chinese Utility Model Patent No. 200820079506.6: Microwave Ultrasonic Wave Combined Catalysis and Synthesis Extractor; Chinese Patent No. 200510122058.4: Resonator with Tuning and Microwave/Ultrasonic Wave Combined for Reinforcing Digestion/Extraction of Sample; and Chinese Patent No. 200610138359.0: Pipeline Microwave Continuous Extraction Device. Although the documents have proved that coordination of microwave and ultrasonic wave can optimize the physical/chemical reactions, microwave can penetrate polytetrafluoroethylene materials and can be reflected in metal, and ultrasonic wave can directly contact with the reactant and can also be disposed on the sidewall of a metal container, in these documents, because the amount of the reactant is small (the largest capacity of the reactor is 2000 mL), magnetic stirring can be adopted, the microwave can directly contact with the reactant, the operator can add the sample in batches and take samples for detection, and the reactor can be conveniently taken out and placed in, simultaneous using of microwave and ultrasonic wave can be easily implemented. However, the reactor is a small laboratory apparatus, and the sample treatment capacity of the reaction system is low; therefore, once the reactor is used in an industrial process, addition of a large amount of raw materials, freely moving and lifting the apparatus, uniformly mixing of heterogeneous reaction materials, and the range of action and the uniformity of microwave and ultrasonic wave cannot be solved by multiple amplification of the capacity of the reaction vessel, that is, these techniques are not suitable for large-scale industrial production, and cannot achieve continuous industrial production.